Limestone geology, also known as Karst, is quite prevalent in the eastern United States. Limestone often dissolves in water, creating voids where groundwater flows like an underground river –gnawing away rock over the eons.
The natural wearing away of limestone over the millenia creates fantastic caves, unique ecosystems and touristic wonders (think Luray Caverns). However, in developed areas, human activities and new development can accelerate the natural pace of erosion–causing sinkholes, threatening buildings and roads, and contaminating groundwater.
